Hot bulb ignition head for a device for firing rough ceramics, particularly bricks

ABSTRACT

A hot bulb ignition head for a device for firing rough ceramics, particularly bricks, serves the intermittent delivery of solid fuel by using compressed air. An explosion takes place in the hot ignition head, which leads to the ejection of the granular solid fuels, particularly coal, into the kiln chamber. It includes a cylindrical head portion with a baffle plate at the outlet end which forms outlet openings. The size of the outlet openings can be adapted to different kiln conditions by insertion pieces.

This application is a continuation of U.S. Ser. No. 433,127, filed Sept.30, 1982, abandoned.

FIELD OF THE INVENTION

This invention relates to a hot bulb ignition head for a device forfiring rough ceramics, particularly bricks, including a connecting tubefor the intermittent delivery of solid fuel by compressed air, acylindrical tube end portion of greater diameter which is connectedfixedly to the connecting tube, and a baffle plate at the outlet endwhich forms at least two outlet openings.

BACKGROUND OF THE INVENTION

Such a hot bulb ignition head is already known from German Pat. No. 2441 680 (which corresponds to British Pat. No. 1 516 877). In thisconventional hot bulb ignition head, the distribution of the ejectedsolid fuel in only one specific direction does not exist. Also thedanger of the destruction of the hot bulb ignition head by theoccurrence of explosions is not entirely excluded and, finally, adaptingthe fuel distribution to different kiln conditions is not possible.

A basic purpose of the invention is to improve the conventional hot bulbignition head so that the danger of destruction or damage of the hotbulb ignition head by explosions is avoided, better fuel ejection in thedesired directions occurs, and favorable adaptation to different kilndimensions and firing conditions is possible in a simple manner.

SUMMARY OF THE INVENTION

This purpose is attained by providing a hot ignition head which includesa connecting tube for the intermittent delivery of solid fuel bycompressed air, a cylindrical tube end portion of greater diameter whichis fixedly connected to the connecting tube, and a baffle plate at theoutlet end of the tube end portion which forms at least two outletopenings. Two opposed, flat plates are secured in the tube end portionparallel to the longitudinal axis thereof and are connected to thebaffle plate at the end of the tube end portion so as to createback-pressure chambers between the plates and the tube end portion.

Due to the hot bulb ignition head being equipped with back-pressurechambers, relatively strong explosions can be controlled without anydanger. The opposed outlet openings with their guide surfaces and guidechambers assure a more accurately aimed ejection of the granulated solidfuel. Finally the insertion pieces permit a simple and quick adapting ofthe firing process to varying firing conditions, such as oven crosssections and the like. Furthermore, the igniting areas for the fuel areconsiderably enlarged, so that a more effective explosion can beachieved.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be discussed in greater detail hereinafter inconnection with an exemplary embodiment which is illustrated in thedrawings, in which:

FIG. 1 is a side view of a hot bulb ignition head for a device forfiring rough ceramics, particularly bricks;

FIG. 2 is a top view of the ignition head of FIG. 1;

FIG. 3 is a cross sectional view taken along the line III--III of FIG.1;

FIG. 4 is a bottom view of the hot ignition head of FIG. 1;

FIG. 5 is a side view of an insertion piece for a baffle plate which isa component of the head of FIG. 1; and

FIG. 6 is a top view of a different insertion piece.

DETAILED DESCRIPTION

The hot bulb ignition head 1 which is illustrated in FIG. 1 has acylindrical connecting tube or conduit 2 through which the hot bulbignition head can be connected to a feed device which intermittentlysupplies the hot ignition head, which is inside of a kiln, with solidfuel for example in the form of granular coal, using compressed air. Theamounts of fuel and compressed air delivered are measured so that anexplosion occurs in the hot bulb ignition head, by which the solid fuelparticles are ejected from the hot bulb ignition head and distributedover the kiln cross section.

An elongate, hollow body member, here a cylindrical tube end portion 3,is fixedly connected to the connecting tube 2, the inside diameter ofthe tube end portion 3 being larger than the inside diameter of theconnecting tube 2. The tube end portion 3 is welded at its upper end tothe connecting tube 2, if necessary by inserting a front flange 4.

Two plane, side plates 5, 6 which face one another are fixedly connectedto the inside wall of the tube end portion 3. As shown in FIG. 2, theside plates 5, 6 extend on a chord to the cylindrical tube end portion3. For this purpose, the longitudinal edges 7 of the side plates 5, 6are welded to the inside wall of the tube end portion 3. Back pressurechambers 8 are formed between the side plates 5, 6 and the inside wallof the tube end portion 3, which chambers 8 open toward the end of theconnecting tube 2 and communicate with the central chamber part of thetube end portion 3.

The side plates 5, 6 project toward the outlet end of the tube endportion 3 past the lower edge 9 thereof and support a transverselyextending baffle plate 10. The side plates 5, 6 and baffle plate 10 arepreferably formed by a single U-shaped part.

The baffle plate 10 and side plates 5, 6 form, together with the tubeend portion 3, laterally opposed outlet openings 11, 12.

The side plates 5, 6 which project past the edge 9 each have apassageway or an orifice 13, 14 (FIGS. 3 and 4) offset relative to eachother and to a longitudinal central plane of the tube end portion 3.

Crossbars 15, 16 which extend transversely to the longitudinal axis ofthe tube and which also have the passageways or orifices 13, 14 aresecured to the projecting ends of the side plates 5, 6. The crossbarends 17, 18 project preferably equally beyond both edges of the plates5, 6 and the equally wide baffle plate 10. They thus form lateralboundaries of and guide surfaces for the outlet openings 11, 12.

Opposed guide plates 19, 20 are secured to the lower edge 9 of the tubeend portion 3. The portion of these plates which projects to the levelof the baffle plate 10 is curved. A longitudinal edge of each guideplate, which edges are displaced with respect to one another, is weldedto a respective crossbar 15, 16, while the opposite edges are spacedfrom the crossbars 15, 16. For fuel particles and gases or compressedair entering guide chambers 21, 22 through the outlet openings 13, 14the guide chambers 21, 22 open downwardly and toward opposed sidesthrough the outlet openings 23, 24. Thus, the fuel can be distributedthrough the center kiln region. The guide chambers 21, 22 alsocommunicate upwardly with the chambers 8.

The baffle plate 10 has a central opening 25, into which can be inserteda flat locking pin 26 provided on an insertion plate 27 or a U-shapedinsertion piece 28. Plural stacked plates 27 or the U-shaped insertionpiece 28 fit between the side plates 5, 6 and their ends project beyondthe baffle plate 10. By inserting one or more stacked plate-shapedinsertion pieces 27, the outlet openings 11, 12, 13 and 14 can be variedin size. With this, an adapting of the fuel distribution to varying kilndimensions or firing conditions is possible. The effective cross sectionof the orifices 13, 14 can also be varied with the U-shaped insertionpiece 28 by means of the height of the laterally turned-up edges 29, 30.U-shaped and plate-shaped insertion pieces 27, 28 can also be usedtogether.

The hot bulb ignition head and the insertion pieces consist of aheat-proof metal, preferably steel.

In operation, the oven in which such hot bulb ignition heads are used isinitially heated to an appropriate working temperature as explained inmy British Patent No. 1 516 877 mentioned above. At this temperature,the metal of the hot bulb ignition head will glow or become red hot. Atthis point, the introduction of granularized coal into the interior ofthe hot bulb ignition head will cause the granularized coal to becomeheated and, in the process of being heated to a glowing state, give offa gas. This gas will mix with the air driving the incoming coal into thehot bulb ignition head and, due to the presence of the glowing coals,create an explosion within the hot bulb ignition head. The resultingpressure wave in the chamber will generate a strong swirling of the hotair therein as well as the coal particles that have not turnedcompletely into ash as yet. Thus, a very uniform distribution of burningcoal granules and the hot air generated thereby is created and resultsin a uniform firing of the temperature of the oven at the workingtemperature. The explosive forces are controlled by the swirling air andignited particles moving into the back-pressure chambers and thence intothe chambers 21, 22 and to the outlet openings 23, 24. The effectivesize of the openings 13, 14 is controllable by use of the aforesaidinsertion plates 27 and 28.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A hot bulb ignition headadapted for receiving therein a solid fuel, comprising:an elongatehollow body member of finite length and defining a central chambertherein; an elongate hollow connecting conduit connected to one end ofsaid hollow body member and for the intermittent delivery of solid fuelby compressed air, the interior of said connecting conduit being in opencommunication with said central chamber, said hollow body member havinga larger diameter than said connecting conduit; a pair of side platesoppositely disposed in said hollow body member and secured to theinterior wall of said hollow body member along lateral edges thereofextending coextensively with the longitudinal axis of said hollow bodymember, said side plates extending beyond the other end of said hollowbody member remote from said connecting conduit, the terminal ends ofsaid side plates terminating externally of said hollow body member, eachsaid side plate between said lateral edges thereof being spaced fromsaid interior wall of said hollow body member to define a back-pressurechamber which opens outwardly of said hollow body member at said otherend; and a baffle plate secured to and extending between the terminalends of said side plates located externally of said hollow body member,the mutually adjacent edges of said baffle plate, said side plates andsaid hollow body member defining oppositely and radially facing firstopenings between said central chamber and the exterior of said hollowbody member.
 2. The hot bulb ignition head according to claim 1,including means defining a radially facing second opening in each saidside plate on the portion thereof external of said hollow body member;anda pair of opposed guide plates secured to said hollow body member andextending in a radially spaced relation into radial alignment with saidsecond openings to define a pair of guide chambers each contiguous witha said back-pressure chamber to deflect ignited fuel as it exits saidignition head.
 3. The hot bulb ignition head according to claim 2,wherein said side plates and said baffle plate are portions of a singleU-shaped piece.
 4. The hot bulb ignition head according to claim 2,wherein plate-shaped crossbars are secured to the portion of said sideplates projecting from said hollow body member, the projecting ends ofsaid crossbars forming, together with said guide plates, said guidechambers.
 5. The hot bulb ignition head according to claim 2, includingat least one insertion piece and mounting means for accommodating amounting of said insertion piece on said baffle plate, said insertionpiece, when mounted on said baffle plate, blocking a portion of saidfirst and second openings.
 6. The hot bulb ignition head according toclaim 5, wherein said mounting means comprises a central opening in saidbaffle plate and said insertion piece has a locking pin receivable insaid central opening.
 7. The hot bulb ignition head according to claim5, wherein said insertion piece is U-shaped in cross section, the legsof the U, when said insertion piece is mounted on said baffle plate,blocking a portion of said second openings.
 8. The hot bulb ignitionhead according to claim 5, including plural insertion pieces, eachhaving stacking means thereon enabling a stacking of said pluralinsertion pieces one on top of the other to block a greater portion ofsaid first and second openings.
 9. The hot bulb ignition head accordingto claim 1, wherein said hollow body member is cylindrical in shape. 10.The hot bulb ignition head according to claim 9, where said side platesare each secured on a chord to the interior of said hollow body member.